Yes, Rafa said there's edema (swelling) on his back.
http://rafaelnadalfans.com/2014/01/29/rafael-nadal-talks-about-his-back-injury-rehab-and-returning-to-tennis/
I don't know much about this kind of thing, but I'm thinking this means it wasn't back spasms, which is what they had thought it was?.
He said he had felt something, though minor, at Canada last year. They need to look into it and be careful 
I cannot imagine -30 degrees. The most we ever get around here (Chile) is, I don't know, -5 I guess. Most people do not have heat in their houses though, so it can feel really cold.
I thought Chile was a warm country. I never imagined it got cold there at all.
That's interesting about no heat in the houses.
I've never heard of that.
So Chile actually gets cold? And people don't have heat? That's sounds so strange. What do they do in the winter?